A genre is an expectation. Certain things are supposed to happen. Take the romance genre--there's suppose to be love, lust, and seduction, and a happy ending. Won't work if at the end a bunch of vampires appear on the scene and kill the happy couple. "The end." Some friends suggested I join them at a "healthy" restaurant in Santa Fe. I ordered a pizza. What arrived was a flattened bed (crushed) of lettuce covered with fresh tomatoes slices and a few flakes of shredded cheese. That's a salad, not a pizza! It's not that it was bad, per se. It's that my taste buds on that evening wanted a pizza.
In looking for a genre book, I am hungering for a particular kind of book. A romance is neither better nor worse than gothic horror--it's a matter of taste and expectation. As a potential reader, genre helps me align my story taste buds with the possible books. Today I'm in the mood for romance, tomorrow it might be gothic horror. The genre helps me to get to the right restaurant, or at least to the right section of the menu.
This works well in a defined world, but what of fusion where there is a mixing and recombining of genres? Neither fish nor fowl. Sometimes these are big breakout hits, while other times they are flops, but probably most never get noticed because most of us don't know what to make of them. Our story taste buds are unacquainted with that mixture of things.
I write about this because I am thinking about this for my current genre and getting it exactly right is a bit like pinning the tail on the donkey. Which genre does the book fit in? Does a genre even exist for this book?
While picking the right title for the book is important, in the end getting it classified within the right genre (which might be quite amorphous and diverse) is a challenge which is at least equal in magnitude.
Oh the woes of writing.